This application is a continuation of Ser. No. 11/445,424, filed on Jun. 1, 2006, now U.S. Pat. No. 7,214,678 which is a continuation of Ser. No. 10/938,792, filed on Sep. 10, 2004 now U.S. Pat. No. 7,098,223 which is a continuation of Ser. No. 10/232,264, filed Aug. 29, 2002, now U.S. Pat. No. 6,825,221 which application is based on, and claims the benefit of, U.S. Provisional Application No. 60/346,844, filed Oct. 18, 2001, and entitled ARYLSULFANYL AND HETEROARYLSULFANYL DERIVATIVES FOR TREATING PAIN, and which is incorporated herein by reference.